LABORATORY ACTIVITIES 3D Modeling Molecular Structures PRE-­‐LAB ASSIGNMENT/QUESTIONS 1. Before the lab, follow the lab manual to download and install the program on your laptop. Get familiar with the user interface and the function of the buttons. 2. Read the chapters related to the fundamental theory about Lewis structures and VSEPR (chapter 13, pages 622-­‐626 and 637-­‐645 in Chemical Principles). 3. Consider the molecules in the table and fill in the electron and bond properties. Be careful, some molecules are typical exceptions to the octet rule. Formula
# of Valence
Electrons
Lewis
Structure
Central
Atom
# of
Sigma Bonds
# of Lone Pairs
on the Central Atom
NCl3
ClF3
BF3
SF6
3D Modeling Molecular Structures PRE-­‐LAB ANSWER SHEET 3. Consider the molecules in the table and fill in the electron and bond properties. Formula
# of Valence
Electrons
Lewis
Structure
Cl
NCl3
N
Central
Atom
# of
Sigma Bonds
# of Lone Pairs
on the Central Atom
N
3
1
Cl
3
2
B
3
0
S
6
0
Cl
26
Cl
F
ClF3
28
F
F
Cl
F
24
BF3
B
F
F
F
48
SF6
F
S
F
F
F
F